Referring to FIGS. 1 and 2, a conventional sealing cap, disclosed in Taiwanese Invention Patent No. I418508, is removably attached to a container 10. The sealing cap includes an outer cap 11, an inner cap 121, an air-tight gasket 122, a resilient member 13 and an operator unit 14. The outer cap 11 is configured to be disposed on the container 10, and includes two pivot portions 110 and a through hole 112 disposed between the pivot portions 110. Each pivot portion 110 has a slot 111. The inner cap 121 is movably connected beneath the outer cap 11. The air-tight gasket 122 is sleeved around the inner and outer caps 11, 121. The resilient member 3 is abuttingly disposed between the outer and inner caps 11, 121. The operator unit 14 includes a connector 141, an operator 142 and a pivot pin 143. The connector 141 extends through the through hole 112 and is connected to the inner cap 121. The operator 142 is pivotally connected between the pivot portions 110 of the outer cap 11 through the pivot pin 143 extending through the slots 111 of the pivot portions 110 and pivotally connecting the operator 142 to the pivot portions 110.
As shown in FIG. 2, when the operator 142 is placed upright on the outer cap 11 to move the inner cap 121 to an unpressurizing position, the inner cap 121 unpressurizes the air-tight gasket 122 against the container 10, and the pivot pin 143 abuts against bottom ends of the slots 111. When the operator 142 is rotated downward to abut against the lateral wall of the outer cap 11, the inner cap 121 is moved upwardly to a pressurizing position, such that the inner cap 121 pressurizes and deforms the air-tight gasket 122 against the container 10.
The conventional sealing cap is conveniently operable to removably seal the container 10. However, because the operator unit 14 and the resilient member 13 are centrally connected to the outer and inner caps 11, 121, the exerting force on the operator unit 14 and the urging force of the resilient member 13 may be localized at the center of the outer and inner caps 11, 121. In use, the conventional sealing cap may be subjected to an unbalanced force, which may cause the inner cap 121 to be oblique relative to the outer cap 11.